Extraction of lithium calcium,and magnesium bromides using hydroxyethers and glycols



United States Patent Int. Cl. B01j 9/04 US. Cl. 23312 10 Claims ABSTRACT OF THE DISCLOSURE A process for the selective extraction of bromine values and the associated metal values thorn brines which comprises intimately contracting said brine with certain glycol derivatives or hydroxyl-containing polyethers as extraction agents. After contact, the extraction agent containing the bromine and metal values is separated from the depleted brine.

This invention relates to a process for the extraction of brines, and more particularly relates to a process for extracting bromine and metal values from brines containing the same.

For many years, brines have been known to be a valuable source for halogens, for sodium and potassium chlorides, for Na and K and for other valuable metals. Since bromine and other values such as metals occur in brines in relatively small quantities as compared to the sodium or potassium chloride, special methods have been necessary for their separation. For instance, bromine has been recovered by acidifying and air blowing certain brines. Likewise, recovery has been effected electrolytically and by treating the brine with an insoluble chemical which is reactive with bromine values. While some of these processes have been used commercially, they have been inetficient, costly and generally unsatisfactory.

It has now been discovered, however, that bromine and metal values may be selectively extracted from brines by intimately contacting said brine with an organic extraction agent, separating said organic extraction agent from said brine and subsequently removing the bromine and metal values from the organic extraction agent.

Whether or not a particular polar organic compound may be used as a selective brine extraction agent is, in general, not predictable in advance. It has been found that a few limited classes of compounds are operative but in other classes even next adjacent homologues may produce pronounced differences in result. All operative compounds, however, appear to produce exceptionally good selectively and capacity. It has been found that the organic extraction agents possessing the ability to selec-' tively extract bromineand metal values from brines containing the same are glycol derivatives or hydroxyl containing polyethers selected from one otf the [following groups:

(1) A hydroxyether halving the formula wherein n represents a number of from 1 to about 8 and R represents. a hydrocarbon radical containing from 4 to about 20 carbon atoms;

(2) IA. member selected from the group consisting of the phenyl ether of dipropylene glycol, the nonyl phenyl ether of dipropylene glycol, the methyl ether of tripropylene glycol, the methyl ether of tetrapropylene glycol, the amyl ether of tetrapropylene glycol, the hydroxyethyl ether of tripropylene glycol, bis(2-phenyl-2-hydroxyethyl ether) of tripropylene glycol, bis(2-phenyl-2-hydroxyethyl ether) of dipropylene glycol, dimethyl ether of diethylene glycol, butyl isopropyl diether of diethylene glycol.

(3) Polypropylene glycols having an average molecular weight of [from about 200 to about 1000.

(4) -Diethers of ethylene glycols have the formula wherein n is a number from 2 to 8.

(5) A glycerine initiated polyalkylene glycol having the formula 5 H-C-O-(CHz-C (OHQH-O) =(CzH40).H

H- O-(OHz-C(CH3)HO)x(C H -O).H

5-? -0(oH,o (CH3)H-0) x (C2H4-O) .11

wherein x and a are numbers such that the average molecular weight of the compound is between 800 and 4000 and a equals from 525% of the sum of a-l-x.

The organic extraction agents used herein are polar compounds which are at least slightly miscible with water. Generally they will form two phases with brine more readily than with plain water. If, however, the layer separation does not occur or occurs to a lesser extent than is considered desirable for a particular operation,

any suitable substantially saline water-immiscible organic diluent such as benzene, hexane, or ethylene dichloride may be added to improve phase separation. When a saline water-immiscible organic diluent is employed to improve phase separation, it has been found that no more of such diluent should be employed than is necessary to produce the desired phase separation. Excessive amounts of diluent tend to interfere with the selectivity of the solvent.

Brines suitable for extraction with these polar organic extraction agents include those sodium and potassium chloride brines containing as little as 10 ppm. bromine values occurring as bromides. These bromine values and the associated metal values may then be selectively extracted from the brines while extracting only minimal amounts of chlorides. Brines which contain significant concentrations of lithium bromide are especially suitable.

The ratio of organic extraction solvent to brine is not critical to the operation of this process but, in general, a range of 1/10 to 10/1 by volume is desirable.

Treatment temperature and pressure during the extraction may be varied to fit the physical characteristics of the particular solvent employed but ambient temperatures and pressures are generally suflicient. For the more volatile solvents, of course, lower temperatures or increased pressures may be advantageous while the more viscous solvents may require some increase in temperature or decrease in pressure to achieve maximum efliciency. Also, it is generally true that for a given solvent, the lower the temperature, the greater the Br extraction will be.

Contact time between the organic extraction solvent and the brine, prior to layer separation may vary over a wide range. In general, however, the contact time required to absorb a significant quantity of bromine and rnetal values has been found to be relatively short. Generally, any time in excess of 5 minutes is suitable and times in excess of 60 minutes are not harmful but are generally of no particular advantage. Contact times of less than 5 minutes can usually be employed, however, if sufiicient agitation is used to insure adequate contacting of the two phases during this period.

After the organic extraction solvent and brine have formed into discrete layers, separation may be accomplished by simply draining off one or both layers, either batchwise or continuously. Once the organic extraction layer has been isolated from the brine layer, recovery of the bromine and metal values may be effected in any suitable manner.

formed and settled. The layers were separated and an analysis was conducted to determine the bromine and metal values extracted. The results of these experiments were as follows:

TABLE I Aqueous Layer Organic Layer after Extraction after Extraction Wt. Wt. P.p.m. Percent Percent P.p.m Run No. Organic Extraction Agent Br Organic 1120 B r 1 Methyl ethJeErI of tripropylene glycol (HO CH2C(CH3)H O' CH2C(CH3)H-OCH2C(CH3) 3, 200 9. 11.1 720 O 3 2 Butyl ether of diethylene glycol (HOCHzCH2OCHzCH2OC4H 20. 8 1, 700 3 Dimethyl ether of diethylene glycol (CH;OCH2CH2-O-OH2CH -OGH 10. 0 400 4 2-octyl ether of diethylene glycol HOOH2-CHTOCH2CH2OC3H17 6. 6 850 Phenyl ether of diethylene glycol HO-CHzCH OCH -OH O-Cflh 9. 49 1,300 Amyl ether of diethylene glycol HOCH2CHz-O-CHzCHz-O-C5Hn 0. 4 12. 9 1,300 7 2ethyl hexyl ether of diethylene glycol HO CHZ-CHZ' O'CH2 CH2OCI{2C(C2115) 0. 1 5.2 440 HCHz-CH2CHz-CH s Isobutylether of diethylene glycol HOCH2CH2O-CH2CH2OCH2-C(CH3)HCH3 20. 0 1, 800 9 Dodecyl ether of diethylene glycol HOCHOHzOCHz-CHz-OC 11 150 1 3-hegtyl ether of diethylene glycol HOCH2-CH2OCHr-CHz-OC(C2H5)H(CHZ)3 5. 470

3. '7 11 Cyclohexyl ether of diethylene glycol HO-CHz-CI-I OOH CH -O 15. 6 1, 900

CHCH2-CHzCHz-CHz-CHz.

Bis-2-phenyl-2-hydroxyethyl ether of diethylene glycol (CaH )C(OH)H-CHzOCHz-CHz 6. 49 1,100

OCHzCH2OCH2-H(OH)C(CGH5). 13 Glyccrine initiated polypropylene oxide having an average mol. wt. of 3,700 capped with ethylene oxide O-O-(OH2O(OH )H0)X(OHzOH2-O-) RE where xzzgy and agcgb 2 3) O)y(CH2CHz-O)bH -O-(CH2C (CH3)H-0-)z(CH2CH2O-) CH 3, 700 0. 5 3. 8 190 14 Glycerine initiated polypropylene oxide having an average mol. wt. of 1,000 capped with 10% by 2,800 3. 4 20. 6 1, 500

weight ethylene oxide. 15 Polypropylene glycol having average mol. wt. of -400 HO(CHzO(CH )H-O).,H 3, 200 9. 0 11. 1 720 16 n-Hexylether of diethylene glycol HOCHyCHzOCH2OHgOC6H1 11.8 1, 700 17 n-Heptyl ether of diethylcne glycol HOCHZ-OHTOCHZCH OC1H 9. 3 1,300 18 ButyElI isopropyl diether of dicthylene glycol C-iH9O-CH2CHzOCHz-CHg-OCH 11. 3 1, 000

3 2' 19 Glycerine initiated polypropylene oxide having an average mol. wt. of 1,501 capped with 10% 3,800 0. 5 7.9 440 ethylene oxide.

For instance, the solvent may be separated from the Example II extracted materials by standard methods such as distillation.

Example I In all of the following extraction experiments, a brine was employed which contained 74 parts by weight of water, 9 parts by weight CaCl 1 part by Weight MgCI 16 parts by weight NaCl and 4400 ppm. Br occurring about one half as LiBr and one half CaBr (by weight). To 100 ml. of brine was added 100 ml. of solvent, the mixture was agitated about minutes at about 75 F. and then allowed to stand until the distinct layers had To a measured amount of the brine of Example I was added a measured amount of organic extraction agent (mono-n-butyl ether of diethylene glycol). The liquids were thoroughly agitated in a graduated container at about F. then the mixture was allowed to stand in a graduated container until two layers formed. The volume of each layer was measured by reading the volume marking at the interface. Incremental amounts of water-immiscible liquids of the kinds indicated in the following table were added to aid in the layer separation, the mixtures being thoroughly agitated and allowed to stand and equilibrate between each addition of water-immiscible liquid. The following tabulates the results obtained:

TABLE 11 Water Organic layer layer after after M1. M1. Ml.of Water-immiscible mixing mixing Brine Solvent liquid added 25 31. 5 18. 0 25 25 31. 5 19.0 25 25 33.0 20.0 25 25 34. 5 21. 0 25 25 36. 5 21. 5 25 25 31. 5 18. 5 25 25 33. 0 20. 0 25 25 36. 0 20. 0 25 25 1 ml. ethylene 31.0 19. 5 25 25 4 ml. ethylene dichloride 32.0 21. 5 25 25 7 ml. ethylene dichloride 34. 5 22. 5 25 25 11 ml. ethylene dichloride. 39. 0 23. 0 25 25 1 ml Stoddard solvent 32. U 18. 5 25 25 4 ml stoddard solvent. 34. 0 20. 0 25 25 7 ml. stoddard solvent. 37. 0 20. (l 46 12 3 ml. heptane 16.0 45. 0 25 25 d0 24. 0 26.0 25 25 2 ml. hexane- 26. 0 26.0 25 25 4 ml. hexane 27. 0 27. 0 25 25 10 ml. hexane 33. 0 27. 0

agent.

5 Example III Employing the general procedure and the same brine composition of Example 1, the following compounds were mixed withthe brine and agitated as 23 C. for about To 100 ml of this brine was added 100 ml of n-hexyl ether of diethylene glycol. The mixture was agitated in a separatory funnel at about 23 C. and allowed to stand until the phases separated. Analysis of the phases proone hour, allowed to separate into layers and analyzed. 5 duced the following results.

The results were as follows:

TABLE III Wt. Wt. percent percent Br in H O in Organic Organic Name phase phase Hexyl ether of triethylene glycol 12 16. 2 Butyl ether of triethylene glycol. 17 27. 3 Phenyl ether of dipropylene glycol 018 3. 75 Amyl ether of triethylene glycol..- 14 18. 43 Phenyl ether of triethylen glycol 088 7. 81 Bis (2-phenyl-2-hydroxy ethyl ether) of heptaethylene glycol 11 16. 5 Bis (2-phenyl-2-hydroxy ethyl ether) of trlethylene glycol 08 7. Bis(2-phenyl-2-hydroxy ethyl ether) of dlpropylene glycol 023 5. 8 Amyl ether of tetraproplyene glycol 085 19. 8 Bis(2-phenyl-2-hydroxy ethyl ether) of heptaethylene glycol... 13 11. Methyl ether of tetraproplyene glycol 024 6. 8

Example IV Weight percent t m gins. H2O Br 01 Top Phase (solvent)-.. 102.1 10. 3 0. 093 1.05 Bottom Phase (aqueous 110. 65 0. 38 32. 6

being allowed to stand. After the mixtures two-phased, claims.

the phases were analyzed and the results are as shown in Table IV.

I claim: 1. An improved process for the selective extraction of TAB LE IV Brine Organic Phase Aqueous Phase Wt. Wt. Wt. Wt. Percent Percent Wt. Percent P.p.m. P.p.m. percent P.p.m. Percent total Name Br Br H 0 Mg Ca L1 Cl Br Solid Carbon Bis(2-phenyl-2-hydroxy ethyl ether) of diethylene glycol 850 160 6. 7 720 32. 4 3. 8 Do 3, 700 580 6. 8 Nil 18 001 1. 01 3, 000 33. 9 3. 9 n-Heptylether of diethylene glycol 850 250 5. 8 540 33. 5 4. 0

B-heptyl ether of diethylene glycol 700 70 5.0 Nil 03 0005 24 3, 300 32. 7 3. 9

Isobuty ether of diethylene glycol 850 240 11.6 560 30. 6 1. 8

Do 3, 700 690 12. l 04 65 0054 2. 94 3, 000 31. 7 1. 7 Cyclohexyl ether of diethylene glycol 850 170 9. 3 610 31. 6 1. 5 Do 3, 700 550 9. 6 0. 3 56 0047 2. 31 3, 000 31. 1 1. 6 2-ethyl hexyl ether of diethylene glycol. 850 4. 3 950 31. 5 1.1 Do 3, 700 4. 1 02 14 0014 3, 400 80. 8 1. 4 Arnyl ether of diethylene glycol 850 8. 5 690 34. 5 3. 3 Do 3, 700 330 8.8 02 36 0035 l. 71 3, 100 32. 4 3. 3 Phenyl ether of diethylene glycol. 850 8. 8 740 30. 1 1. 2 Do 3, 700 580 8. 9 01 19 0018 1. 67 3, 100 30.1 1. 4 2-octyl ether of diethylene glycol-.. 850 380 5. 0 470 33. 0 2. 4 Do 3, 700 570 4. 9 Nil 08 0009 61 3, 000 31. 9 3. 4 n-Hexyl ether of diethylene glycol. 850 320 6. 9 630 31.6 1. 7 D 3, 700 570 7. 1 01 34 0033 1. 52 3, 200 30. 6 1. 5

metal bromides selected from the group consisting of lithium, calcium and magnesium bromides from brines containing both chlorides and said bromides which comprises intimately contacting with said brine an organic extraction agent which is a member selected from the group consisting of (l) a hydroxyether having the formula:

where n represents a number of from 1 to about 8 and R represents a hydrocarbon radical containing from 4 300 75 to about 20 carbon atoms; (2) a group consisting of the phenyl ether of dipropylene glycol, the nonyl phenyl ether of dipropylene glycol, the methyl ether of tripropylene glycol, the methyl ether of tetrapropylene glycol, the amyl ether of tetrapropylene glycol, the hydroxyl ether of tripropylene glycol, bis(2-phenyl-2-hydroxyl ethyl ether) of tripropylene glycol, bis (2-phenyl-2-hydroxy1 ethyl ether) of dipropylene glycol, dimethyl ether of diethylene glycol and butylisopropyl diether of diethylene glycol; (3) polypropylene glycols having an average molecular weight of about 200 to about 1000; (4) diethers of ethylene glycols having the formula:

wherein n represents a number of 1 to 8 and R represents a hydrocarbon radical containing from 4 to about 20 carbon atoms.

3. The process according to claim 1 wherein the organic extraction agent is a polypropylene glycol having an average molecular weight of from about 200 to about 1000.

4. The process according to claim 1 wherein the organic extraction agent is a diether of polyethylene glycol having the formula:

HOC (C H HCH O'(CH CH O CH CH C H OH wherein n is a number from 2 to 8.

5. The process according to claim 1 wherein the organic extraction agent is a glycerine initiated polyoxyalkylene glycol having the formula:

wherein x and a are numbers such that the average molecular weight of the compound is between 800 and 4000 and a equals from 5 to 25 percent of the sum of a plus x.

6. The process of claim 1 wherein the organic extraction agent is the n-butyl ether of diethylene glycol.

7. The process of claim 1 wherein the organic extraction agent is the methyl ether of tripropylene glycol.

8. The process of claim 1 wherein the metal bromide is lithium bromide.

9. The process of claim 1 wherein the organic extraction agent is the n-hexyl ether of diethylene glycol.

10. The process of claim 1 wherein the organic extraction agent is the isobutyl ether of diethylene glycol.

References Cited UNITED STATES PATENTS 2,561,862 7/1951 Hill 23-312 X 2,847,279 8/ 1958 Tucker 23-312 X 2,968,523 1/1961 Cunningham 23312 X 2,969,275 1/1961 Garrett 23-312 X 3,101,250 8/1963 Schoenbeck 23-87 3,107,154 10/1963 Schacter 23-216 X 3,219,409 11/1965 Asher 23-89 3,214,248 10/1965 Schwenk 23-312 NORMAN YUDKOFF, Primary Examiner.

S. I. EMERY, Assistant Examiner.

US. Cl. X.R. 2389, 90, 91 

